The invention relates to a process and an apparatus for casting metallic materials, and more particularly to a process and an apparatus for casting metallic materials which are in a semi-solid state.
U.S. Pat. No. 4,694,882 describes the use of a semi-solid metallic material for casting, employing an extruder for processing the metallic material in semi-solid form. The process described therein has a number of disadvantages, in particular relating to the use of a processing assembly in form of an extruder with a thrust screw.
WO00/41831 discloses a different approach whereby semi-solid metallic material is processed using a so-called warm-chamber-casting process. This published application describes using a conventional heating chamber for transforming the solid metallic material into a semi-solid state. An injection unit which operates like a sump pump is immersed in the heating chamber. The temperature of the semi-solid material is then equalized by the surrounding heated metallic material. However, this apparatus enables only batch operation and not continuous operation.
It would therefore be desirable and advantageous to provide an improved apparatus for casting metallic materials, which obviates prior art shortcomings and enables continuous operation.